Air-Sea CO2 fluxes

Description

Data wind speed 10m (m/s):

→ Azur buoy (model) - 2009-2022
→ EOL buoy (model) - 2009-2022

Frequency : Hourly
Unit : m/s

Histogram of wind speed distribution : pelagic (Azur buoy) vs coastal (EOL buoy)

Annual means of wind speed (2009-2022) : EOL buoy

Data pCO2 water Point B (µatm):

period : jan.2007 - dec.2022

Surface data,
Frequency : Weekly (every tuesday at 09 AM)
Unity : µatm

Annual cycle of seawater pCO2 at Point B (2007-2022) :

Calculation of NpCO2 & TpCO2 and deltas :

NpCO2 = non-temperature effects on pCO2 water variations

TpCO2 = only temperature effects on pCO2 water variations

→ Calculation of deltas :

  • delta pCO2(T) = temperature effects = pCO2 water - NpCO2

  • delta pCO2(bio) : biological effects = pCO2 water - TpCO2

Atmospheric and seawater pCO2 (µatm) according to time (2007-2022) :

Air-sea CO2 fluxes

Flux calculation

→ negative values = flux into the ocean

Method used : Wanninkhof (2014)

Method used : Wanninkhof (1992)

Formulas :

  • K600 = 0.266 * U²

  • SC = 2073.1 - (125.62 * T) + (3.6276 * T²) - (0.043219 * T^3)

  • k = K600 * (SC/600)^0.5 (cm/h)

  • K0 = Henry’s constant (seacarb)

Final formula : F = k * K0 * ΔpCO2

unity : mol of C / m² / year

Plot comparing the 2 CO2 fluxes :

Annual fluxes (Wanninkhof, 2014)

## [1] 0.1390504

Comparison with DE CARLO results (jan.2007 - oct.2011)

Point B : 2009-2011, so comparison for 2009-2011 period

## [1] -1.649429e-06

De Carlo (2007-2011) :
- average hourly flux : -2.19e-05
- annualized flux (by year) : -1.91e-01
- maximum hourly flux (winter) : -4.57e-04
- minimum hourly flux (summer): 4.29e-04

De Carlo (01/06/2009 - 10/04/2011) :
- average hourly flux : -2.77e-05
- annualized flux (per year) : 2.42e-01
- maximum hourly flux (winter) : -4.57e-04
- minimum hourly flux (summer): 4.29e-04

Point B (01/06/2009 - 10/04/2011) :
- average hourly flux : -1.65e-06
- annualized flux (by year) : 1.45e-02 - maximum hourly flux (winter) : -3.23e-04
- minimum hourly flux (summer) : 5.70e-04